The early members of the Church of Jesus Christ of Latter-day Saints (commonly called the "Mormon" church) didn't just move straight from New York to Utah... the move took 14 years! So the reasons vary. Only about a year after the Church was organized, most of it's members moved from New York to Kirtland, Ohio. This is because a large group of people in Kirtland had joined the Church, and it was decided that it would be best for the New York members to move to join these new Ohio members. Soon after, some groups of Mormons were sent to Missouri to settle what was intended on being Zion, the headquarters of the Church.